Inch thread die FERVI F122 DIN 5158/B for gas pipe threading

Inch thread die FERVI F122 cuts external gas threads on pipe and fittings to DIN 5158/B. HSS steel resists heat and wear during manual threading operations. The dual-entry chamfer centres the die from either face and guides chips away from the cutting zone. This model handles steel, aluminium, cast iron and non-ferrous alloys in gas pipe installations.

Gas threads seal pressurised connections in pneumatic and fluid systems. The F122 die produces accurate external threads on pipe ends and fittings. Manual threading gives the operator direct control over speed and torque. Cutting oil is mandatory to reduce friction and prevent premature edge wear.

Construction and material of the inch thread die

HSS steel and DIN 5158/B geometry

High-speed steel maintains hardness under the heat generated by thread cutting. The DIN 5158/B profile defines tooth angle, pitch and crest dimensions for gas threads. Symmetrical entry chamfers on both faces simplify alignment and reduce starting torque. Flute geometry evacuates chips in the direction of rotation.

• Material: HSS (high-speed steel)
• Standard: DIN 5158/B
• Thread system: Inch (imperial)
• Thread type: Gas thread (parallel or taper)
• Entry design: Dual-face chamfer for centring
• Chip evacuation: Directional flutes
• Operation: Manual threading with wrench or die stock

Surface finish on the cutting edges minimises friction and extends tool life. Hardness remains stable across the working temperature range. Dimensional tolerances ensure thread fit within the DIN 5158/B envelope. The die body withstands the radial forces applied during manual rotation.

Thread pitch and size range

The F122 family covers common gas pipe sizes from G1/8-28 to G2-11. Each die is marked with its nominal thread designation. Pitch values follow the inch standard for gas threads. Operators must match the die size to the prepared pipe diameter.

• Pitch range: 0.5 mm to 2.5 mm (depending on thread size)
• Thread designation: G series (gas parallel) or R series (gas taper)
• Nominal sizes: 1/8 inch to 2 inch
• Marking: Thread size stamped on die face

Correct pilot hole diameter is critical for thread quality. Undersized holes increase cutting force and risk die breakage. Oversized holes produce shallow threads that fail under pressure. Reference tables in DIN 5158/B specify drill sizes for each thread.

Applications of the inch thread die

Gas pipe systems in compressed air, natural gas and hydraulic installations require leak-tight threaded joints. The F122 die cuts external threads on pipe ends, nipples and male fittings. Steel pipe dominates industrial gas distribution. Aluminium and brass fittings appear in lighter-duty pneumatic circuits. Cast iron housings and manifolds also accept gas threads. Field repair and on-site assembly benefit from manual threading tools. Cutting oil must be applied continuously to cool the die and flush chips from the flutes. Rotation speed should match the material hardness to avoid thread tearing or die chipping.

Operating procedure and safety

Preparation and setup

Verify the pilot hole diameter against the DIN 5158/B drill chart. Secure the workpiece in a vice or clamp to prevent rotation. Chamfer the hole entrance to guide the die. Apply cutting oil liberally to the hole and die teeth.

• Check pilot hole diameter with caliper or gauge
• Clamp workpiece firmly to prevent movement
• Chamfer hole entrance at 45 degrees
• Apply cutting oil to die and workpiece
• Align die square to the hole axis

Misalignment at the start produces tapered or crossed threads. The dual-entry chamfer helps self-centre the die if the approach is within a few degrees of perpendicular. Light downward pressure during the first turn seats the die on the chamfer.

Threading technique

Rotate the die clockwise with steady pressure. After each full turn, reverse half a turn to break chips. Reapply cutting oil every few turns. Continue until the thread reaches the required length. Back the die off and inspect the thread profile.

• Rotate clockwise with even torque
• Reverse half a turn every full rotation to break chips
• Add cutting oil frequently
• Monitor chip evacuation through flutes
• Stop when thread length is achieved
• Clean die and workpiece after threading

Excessive force indicates a dull die or incorrect hole size. Chips that pack into the flutes cause scoring and poor thread finish. Clean the die with a brush and solvent after each use. Store in a dry location to prevent rust on the cutting edges.

Technical reference from catalog

FERVI F122 dies conform to DIN 5158/B for gas threads in the inch system. HSS steel composition provides the hardness and toughness needed for manual threading. The dual-entry design allows the operator to start from either face. Chip flutes run parallel to the die axis and clear swarf during rotation. Lubrication with cutting oil is essential to control temperature and reduce wear. Compatible materials include carbon steel, stainless steel, aluminium alloys, cast iron and brass. Thread accuracy depends on correct pilot hole diameter, die alignment and consistent rotation speed. Each die is marked with its thread designation for quick identification.